When two user equipment terminals (e.g., mobile communication devices) of a cellular network or other telecommunication system communicate with each other, their data path typically goes through the operator network. The data path through the network may include base stations and/or gateways. If the devices are in close proximity with each other, their data path may be routed locally through a local base station. In general, communications between a network node such as a base station and a wireless terminal is known as “WAN” or “Cellular communication”.
It is also possible for two user equipment terminals in close proximity to each other to establish a direct link without the need to go through a base station. Telecommunications systems may use or enable device-to-device (“D2D”) communication, in which two or more user equipment terminals directly communicate with one another. In D2D communication, voice and data traffic (referred to herein as “communication signals” or “communications”) from one user equipment terminal to one or more other user equipment terminals may not be communicated through a base station or other network control device of a telecommunication system. “Device-to-device (“D2D”) communication may also be known as “sidelink direct” communication (e.g., sidelink communication), or even as “sidelink”, “SL”, or “SLD” communication.
D2D or sidelink direct communication can be used in networks implemented according to any suitable telecommunications standard. A non-limiting example of such as standard is the 3rd Generation Partnership Project (“3GPP”) Long Term Evolution (“LTE”). The 3GPP standard is a collaboration agreement that aims to define globally applicable technical specifications and technical reports for third and fourth generation wireless communication systems. The 3GPP may define specifications for next generation mobile networks, systems, and devices.
Currently 3GPP is specifying a new feature for Rel-14 that covers use cases and potential requirements for LTE support for vehicular communications services (represented by the term, Vehicle-to-Everything (V2X) Services). The feature is documented in the TR 22.885 on LTE Study on LTE Support for V2X Services. Contemplated V2X services may include one or more of the following:                V2V: covering LTE-based communication between vehicles. A device carried by a vehicle may herein be referred to as a vehicle UE or V-UE.        V2P: covering LTE-based communication between a vehicle and a device carried by an individual (e.g. handheld terminal carried by a pedestrian, cyclist, driver or passenger). A device carried by an individual or person may herein be referred to as a pedestrian UE or P-UE.        V2I/V2N: covering LTE-based communication between a vehicle and anything other than another vehicle unit or pedestrian unit. One example of a V2I/V2N includes an infrastructure entity such as a roadside unit (RSU). A roadside unit is a transportation infrastructure entity (e.g. an entity transmitting speed notifications). Another example of V2I/V2N is a network. Herein reference to “V2I” also refers to V2I/V2N. A device associated with an infrastructure entity or network may herein be referred to as an infrastructure UE or I-UE.        
Vehicle (V2X) communication is described in one or more of the following (all of which are incorporated herein by reference in their entirety):                3GPP TS 36.331 V13.0.0 “Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specification”, including but not limited to § 5.10.3 (Sidelink communication monitoring), § 5.10.4 (Sidelink communication transmission), and § 9.3.2 (pre-configurable parameters).        RP-151109, Feasibility Study on LTE-based V2X Services 3GPP TSG RAN Meeting #68, Malmö, Sweden, Jun. 15-18, 2015.        RP-152293, Support for V2V services based on LTE sidelink, 3GPP TSG RAN Meeting #70, Sitges, Spain, Dec. 7-10, 2015        3GPP TSG RAN WG1 Meeting #84bis, Busan, Korea 11-15 Apr. 2016, Chairman notes.        3GPP TR 22.885 V0.4.0 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Study on LTE Support for V2X Services (Release 14).        
Initially 3GPP deliberations concerning vehicle-to-vehicle (V2V) communications essentially assumed reuse of LTE sidelink for V2V, e.g., assumed that the V2V communications will essentially be indistinct from sidelink direct communications in the access stratum (AS), e.g., may use the same PC5 radio access interface. As such, was initially generally been assumed that the LTE 3GPP resource selection design for SLD would be reused for V2X communication as much as possible. On the other hand, there are still numerous differences between V2X and D2D, such as higher V2X user equipment (UE) density and much higher V2X UE velocity.
Concepts for synchronization and resource pool design regarding V2X including V-UE and P-UE were disclosed in the following United States Provisional Patent applications (all incorporated herein by reference in their entirety):                U.S. Provisional Patent Application 62/313,600, filed Mar. 25, 2016, and U.S. patent application Ser. No. 15/469,103, filed Mar. 24, 2017, both entitled “SYNCHRONIZATION METHOD AND APPARATUS FOR V2X COMMUNICATIONS”.        U.S. Provisional Patent Application 62/315,641, filed Mar. 30, 2016, and U.S. patent application Ser. No. 15/473,121, filed Mar. 29, 2017, both entitled “SYNCHRONIZATION FOR VEHICLE (V2X) COMMUNICATIONS”.        U.S. Provisional Patent Application 62/319,065, filed Apr. 6, 2016, and U.S. patent application Ser. No. 15/477,299, filed Apr. 3, 2017, both entitled “RESOURCE SELECTION FOR VEHICLE (V2X) COMMUNICATIONS”.        U.S. Provisional Patent Application 62/335,609, filed May 12, 2016, U.S. Provisional Patent Application 62/335,609, filed May 14, 2016, and U.S. patent application Ser. No. 15/592,869, filed May 11, 2017; all entitled “entitled “METHOD AND APPARATUS FOR SELECTING BETWEEN OVERLAPPING AND NON-OVERLAPPING RESOURCE POOLS FOR VEHICLE (V2X) COMMUNICATIONS”,        U.S. Provisional Patent Application 62/335,581 filed May 12, 2016, and U.S. patent application Ser. No. 15/592,896, filed May 11, 2017, both entitled “METHOD AND APPARATUS FOR SELECTING RADIO RESOURCES FOR VEHICLE (V2X) COMMUNICATIONS FROM AN OVERLAPPING RESOURCE POOL”.In some aspects of one of more of the foregoing, different service types (V or P) are distinguishable in resource selection.        
Various recent 3GPP RAN agreements in the form of study items and works items have concerned vehicle-to-vehicle (V2V) communications. Among these are the following (all of which are incorporated herein by reference in their entirety):                RP-151109, Feasibility Study on LTE-based V2X Services”, from the 3GPP RAN #68 meeting.        RP-152293, Support for V2V services based on LTE sidelink, from the 3GPP RAN #70 meeting, which gives the highest priority of V2X communications to vehicle UE (V-UE) to vehicle UE communications.        RP-161298, LTE based V2X Services at the most recent 3GPP RAN # 72 meeting.        
The RP-161298 of the 3GPP RAN # 72 dealt with pedestrian UE (P-UE) participating in V2X communications. It was concluded that V2P services where a pedestrian-borne wireless terminal (P-UE) sends V2X messages but does not receive V2X messages is substantially more power efficient than V2P services where the P-UE receives V2X messages from vehicle-borne wireless terminals (V-UEs), which means P2V transmission instead of P2V monitoring at P-UE side should be emphasized. In order to specify enhancements for support of V2P services, “random resource selection for P-UEs potentially on the PC5 resource pool shared with V-UE transmissions, with additional study on sensing operation during a limited time for P-UEs” was proposed.
Sensing before transmission is mandated for V2V transmission in order to reduce random resource selection collision to improve PRR (packet reception ratio) performance. Power consumption of sensing becomes an issue to P-UE in P2V transmission. R1-165208, “Further detail of partial sensing for P2V operation”, NTT DOCOMO, incorporated herein by reference, introduces a partial sensing method for P2V operation, which proposes a UE-specific sensing window with sensing operation in limited time. In the R1-165208 approach, the UE not only receives signaling about common sensing window, but also receives signaling about another specific sensing window. If the UE has to use specific sensing window, then how the UE determines which sensing window to be used is not clear in R1-165208. The R1-165208 thus defines a new specific sensing window, and therefore requires additional signaling, since the common sensing window has already been defined.
There are problems for pedestrian-borne wireless terminals (P-UEs) making random resource selection from a resource pool shared with vehicle-borne wireless terminals (V-UEs), considering the particular service requirements of P-UEs, and considering the fact that the sensing strategy of a V-UE which may share the resource pool. Furthermore, although the P-UE and V-UE may have different Quality of Service (QoS) requirement, there is no priority based strategy for resource selection.
What is needed, therefore, and an example object of the technology disclosed herein, are methods, apparatus, and techniques for radio resources selection and utilization in V2X communications.